The present invention relates to a die/attach composition consisting essentially of a silver filled glass which is slurried in an organic vehicle to form a paste which is applied to the surface of a ceramic support for a semiconductor device. The semi-conductor device is laid down on the paste coated surface of the support and the assembly is dried to remove organic vehicle and then fired to remove all residue of the vehicle from the assembly.
Considerable effort has been exerted over a long period of time to improve the strength of the bond between semiconductor devices and ceramic supports. A recent and extensive review of the development of die/attach compositions has been reported by F. K. Moghadam and published in the proceedings of the 1983 ISHN International Microelectronics Symposium, Oct. 31 - Nov. 2, 1983, Philadelphia, Pa., entitled "Development of Adhesive Die/Attach Technology in Cerdip Packages; Material Issues". Moghadam reports an inorganic die/attach paste manufactured by Johnson Matthey Inc. which in the wet form contains 66.4% silver, 16.6% glass, 1% resin and 16% solvent, which after drying and organic burn-out would be completely inorganic with 80% silver and 20% glass. This paste is identified by the manufacturer as JMI-4613.
U.S. Pat. No. 4,401,767 assigned to Johnson Matthey Inc. and titled, "Silver-Filled Glass", appears to describe the inorganic die/attach paste discussed by Moghadam.
The present invention is directed to a silver-filled glass die/attach composition which is a significant improvement over the silver-filled glass composition described by Moghadam and by the U.S. Pat. No. 4,401,767.